Re: Proper support for PCI-based option rom loading (was Re: [Qemu-devel] Re: qdev property bug?)

[Anthony Liguori <anthony@codemonkey.ws>]

Sebastian Herbszt wrote:
> Anthony Liguori wrote:
>> Gerd Hoffmann wrote:
>>> I'm more worried about the CONFIG_OPTIONROMS_DEPLOYED patches for 
>>> seabios, although I don't fully understand what they are doing.  
>>> There are non-pci option roms (linuxboot, multiboot, extboot) which 
>>> qemu will continue to deploy the way roms are deployed today.
>>
>> That's a good point.  Need to think about how to best handle that.  
>> SeaBIOS supports up to two static option roms so maybe what we need 
>> to do is make use of that mechanism for things like linuxboot/extboot.
>
> Keep loading custom roms (e.g. from -option-rom) with rom_add_file 
> starting at 0xc8000.
> Modify SeaBIOS to scan the memory range for pre-deployed option roms 
> before deploying
> PCI roms. SeaBIOS will find the last pre-deployed rom and have a 
> starting address for
> deploying PCI roms. This will keep ISA option roms working.

If we make -option-rom appear through a PCI device, then DDIM will work 
properly for those roms.  Also, it would be nice if Linux boot used a 
PCI device instead of fw_cfg to load the kernel into memory.

Regards,

Anthony Liguori